Dimmer switch



June 13, 1939. J. R. THORP ET AL DIMMER SWITCH Filed March 27, 1957 I I i l?! I vlilllfili INVENTORS ATTORNEY5.

- Patented June 13, 1939 PATE N T :OFF I C E D-IDIDIER SWITCH Joel R. Thorp and Holdridge 'W. Marsh, West Allis, Wis.,assignors to The Fulton Company, West Allis, Wis., a corporation of Wisconsin Application-March 27, 1937, Serial No. 133,391

9 Claims.

Our present invention relates generally to improvements in switch mechanisms, and relates more specifically to improvements in the construction and operation of so-called dimmer switches for controlling the headlights of vehicles such as automobiles.

Generally defined, an object of our present invention is to provide an improved switch mechanism which is simple in construction and highly 10 effective in use. 7

Some of the more specific objects of the invention are as follows:

To provide an improved dimmer switch which is durable in construction, and which may be manufactured and sold at moderate cost.

To provide a switch assemblage which may be readily manually operated, and which functions with utmost precision.

To provide an extremely compact switch mech- 20 anisrn most of the parts of which may be conveniently manufactured with the aid of punches and dies.

To provide a unitary switch assembly all parts of which are protected against tampering and 5 damage, and which may be readily installed in the lighting circuits of standard automobiles.

To provide improved three-way switch mechanism of the type wherein successive manipulations of the operating button or plunger connect difierent electrical circuits, while alternate manipulations complete the same circuit.

To provide new and useful mechanism for converting the motion of a reciprocating switch actuating member into oscillatory motion of a con- 'tactmember in a plane which'intersects the line of travel-of the reciprocating member.

To provide an electric switch having neat and highly finished appearance, and which may be conveniently assembled and dismantled.

These 'and other specific objects and advantages of our present invention will be apparent from the following detailed description.

A clear conception of one practicableembodiment of the several features constituting this invention, and of the mode of constructing and of manipulating dimmer switches built in accordance with the improvement, may be had by referring to the drawing accompanying and forming a part of this specification wherein like reference characters designate the'same or similar'parts'in the various views.

Fig. 1 is a longitudinal vertical section through the dimmer switch unit, taken along the line 1 l-I .of: Fig; 4,;andshowing theactuatlng plunger in lowermost position with the contact plate in one extreme position;

Fig. 2 is another longitudinal vertical section through the switch unit, taken along the line 22 of Fig. 4, and showing the plunger in upper-3E5 most position with the contact plate in the other extreme position;

Fig. 3 is a part sectional end view of the assemblage showing the actuating plunger positioned as in Fig. 1; and

Fig. 4-is a transverse horizontal section through the lower portion of the switch assemblage, taken along the line"4--4 of Fig. 1 and showing the contact plate in the same position as in Fig. 1.

While our invention has been shown and de- 'lscribed herein as being embodied in a particular type of dimmer switch especially applicable to automobile lighting circuits, it is not intended and attaching plate 6 having a main enclosing casing 1 secured to one side thereof and 'a tubular spring casing 8 projecting from its opposite side and firmly secured to the plate 6 and casing l by means of several integral attaching.:.3 lugs 9; a contact supporting plate 10 preferably formed of insulating material and detachably secured to the open lower end'of the main casing 1 in any suitable manner to complete the enclosure, and'providing an insulated mounting for 3;,

three contacts ll, [2, l3 each of which has a terminal M secured thereto on the othersideof the plate [0; an oscillatory contact plate l5 and an-insulating plate I6 rigidly attached thereto by means of a recessed clamping bracket l1, the

contact and insulating plates l5, It being swingably suspended from the pivot contact II and the former being alternately cooperable'with the fixed contacts l2, [3; a lwf spring l8 secured to the interior of the main casing 1 by means 45 of a clamping strip [9 and having one .end'portion Zliresiliently and slidably engaging the insulating Zplate l6 while its opposite resilient end portion is provided with an elongated opening 2|; a'rotor 22 revolvably mounted upon axflxed transverse shaft 23 rigidly secured to the main casing 8 andhaving alaterally fluted flange 24 cooperable with the central recess in the-bracket I! to oscillate'the plates l5, l6,.the rotor 22 also having an annular series :of peripherallalzlutments 25 cooperable with the end of the spring opening 2I to prevent reverse rotation thereof; a plunger bracket or element 26 having a lower hook or flange 21 cooperable with the rotor abutments 25 to revolve the rotor and having its opposite end firmly attached to an actuating cap 28 slidably embracing the upper end of the tubular casing 8; and a compression spring 29 resiliently engaging the outer side of the element 26 and coacting at its opposite ends with the plate 6 and cap 28 respectively.

The supporting plate 6, casings 1, 8, contact plate I5, rotor 22, plunger element 26 and cap 28, may all be formed'of sheet metal with the aid of punches and dies, and the main casing 1 is of box-shape and has an opening 30 in the top thereof which coacts with the reduced medial portion of the element 26 as shown in Fig. 3. The tubular casing 8 cooperates with the plunger cap 28 to completely enclose the spring 29, and the upper coils of this spring are of reduced diameter and resiliently engage the curved external surface of the element 26 so as to constantly urge the hook flange 21 thereof toward the rotor 22. The element 26 has upper and lower ab'utments 3 I, 32 which are engageable with the main casing 1 adjacent to the opening 36 to limit the downward and upward travel, respectively, of the element 26 and cap 28, as clearly indicated in Figs. 1 and 2; and the spring 29 constantly urges the element 26 and cap 28 toward the position shown in Fig. 2.

The contact plate I5 is spaced from the contact carrier plate ID by means of a flange 33 formed on the pivot contact II; and the plate I5 has dished contact portions alternately engageable with the spaced contacts I2, I3, and may be additionally secured to the backing plate I6 by means of lugs 34 formed integral with the plate I5. The terminals I I and the recessed bracket I1 may also be stamped from sheet metal; and the successive flutes or lateral off-sets of the rotor 22 are so formed that they will successively coact with the bracket I1 to oscillate the contact plate I5 in opposite directionsabout the pivot contact II, as the rotor is revolved by steps each equal to onesixth of a revolution. The lower arm or end portion 26 of the leaf springs I8 constantly urges the contact and backing plates I5, I6 downwardly so as to maintain the plate I5 against the flange 33 and the swinging end thereof in snug engagement with the fixed contacts I2, I3, and this spring portion 20 also serves to produce the desired wiping action at the contacts I2; I3. The other arm of the leaf spring I8 constantly presses against the periphery of the rotor 22 and thus restrains the rotation thereof about the shaft 23, and the successive peripheral teeth of the rotor 22 are adapted to pass through the spring opening 2| While the rotor abutments 25 are successively cooperable with the end of this spring opening to positively prevent reverse rotation of the rotor 22 in the wrong direction when the flange 21 of the plunger element 26 is pushed along the rotor periphery. The rotor supporting shaft 23 which is rigidly attached to the casing 1, has one end portion thereof enlarged'to provide a side abutment for centrally positioning the rotor 22 thereon, and the rotor preferably has a relatively long hub so as to provide ample bearing surface.

7 When the improved dimmer switch assemblage has been properly constructed and installed, the 7 spring and plunger mechanisms will normally be positioned as shown in Fig. 2 with the element 26 fully elevated and the abutments 32 in contact with the casing 1 adjacent the opening 30, and the oscillatory contact plate I5 may be in snug engagement with either of the fixed contacts I2,

I3 but not both. As illustrated in Fig. 2. the plate 5 I5 engages the contact I3 and has illustrated an electrical circuit from the pivot contact II through the plate I5 and fixed contact I3, these current conducting elements being thoroughly insulated from all of the other elements of the assemblage by the insulating plates Ill, I6. When the actuating cap 28 is depressed and the spring 29 is compressed toward the position shown in Fig. 1, the hook flange 21 of the plunger element 26 rides downwardly along and over the periph- 5 eral cam surface of the adjacent rotor tooth, while the rotor 22 is locked against rotation by the leaf spring I8 engaging a rotor abutment 25, until the flange 21 has passed this rotor tooth and the abutments 3| engage the casing 1. The

spring 23 coacts with the outer surface of the element 26 so as to constantly urge the flange 21 toward the rotor tooth and when the flange 21 passes the abutment 25 at the lower end of the tooth, the plunger element 26 is snapped into the 25 position shown in Fig. 1 by this compression spring 29. Upon subsequent release of the pressure on the cap 28, the spring 29 quickly becomes eifective to raise the plunger element 26,

thereby causing the hook flange 21 to engage the 30 adjacent rotor abutment 25 and to thereby move the rotor 22 one sixth of a revolution and restore the spring and plunger mechanisms to the position shown in Fig. 2. This. partial rotation of the fluted rotor 22 by the element 26, causes the adjacent rotor off-set to push the switch contact and backing plates I5, I6 through the recessed bracket I1, and to swing the contact plate I5 about the pivot contact I I until the electrical circuit is completed through the contact II, plateau) I5 and the other fixed contact I2 as illustrated in Figs. 1 and 4. Successive actuations of the cap 28 will thus cause the swingable contact plate I5 to be thrown from one contacting position to the other; and upon release of the actuating pressure, the mechanism will always be returned to the position'indicated in Fig. 2 and will be ready for subsequent actuation.

From the foregoing detailed description of the construction and operation of ourimproved dlmments of the mechanism may obviously be man- 00 ufactured at minimum cost with the aid of punches and dies, and the various parts may be conveniently assembled to complete the structure. The reciprocatory movement of the actuating plunger is effectively converted into oscilla- 5 tory movement of the contact plate I5, by the fluted rotor 22 coacting with the bracket I1, and the abutments 25 of the rotor 22 serve the dual purpose of locking this rotor against reverse .ro-

tation and of effecting an actuating connection with the plunger element 26. The compression spring 29 also serves a dual function in that it returns the plunger element 26 to ormal position when the actuating pressure is rel ased, and also constantly presses the plunger element 26 to- While the assemblage has 55 ward the rotor 22. The leaf spring 2| likewise performs a dual function in that it restrains free rotation of the rotor 22 and locks this rotor against reverse rotation, and simultaneously produces a resilient pressure on the contact plate l5 so as to establish good electrical contact and provide the desired wiping action. While the switch assemblage is especially adapted for use as a dimmer switch in connection with automobile lighting systems, it may obviously be used for other purposes, and the improved switch unit has proven highly successful in actual use. All parts of the mechanism are of durable construction and extended bearing surfaces are provided for the several movable elements, and the working parts are moreover completely enclosed and thus effectively protected.

It should be understood that it is not desired to limit this invention to the exact details of construction and to the precise mode of use herein shown and described, for various modifications within the scope of the claims may occur to persons skilled in the art.

We claim:

1. In a switch, a contact plate pivotally supported upon a fixed terminal and having its swinging end alternately cooperable with independent fixed contacts, a rotor revolvable about an axis disposed laterally of the plane of movement of said plate and extending transversely of the axis of said pivotal supporting terminal and successive peripheral portions formed to oscillate said contact plate in a plane in opposite directions when said rotor is advanced by steps equal to the distance between said successive portions, and an element movable toward and away from said plane to successively advance said rotor by said steps.

2. In a switch, a contact plate oscillatable in a plane about a pivot, a rotor revolvable about an axis disposed parallel to said plane and having successive peripheral teeth which are ofi-set in opposite directions with respect to the central plane of the rotor, and a plunger element movable perpendicular to said plate and engageable with said teeth to cause the latter to successively oscillate said plate in opposite directions.

3. In a switch, an oscillatory contact plate, a rotor revolvable about an axis parallel to said plate and having equally spaced peripheral abutments and oppositely laterally oiT-set portions adjacent to the successive abutments, and a plunger element movable away from said plate to engage said abutments and to cause said off-set rotor portions to successively oscillate said plate in opposite directions.

4. In a switch, a contact plate swingably mounted upon a fixed terminal and having its swinging end alternately cooperable with independent laterally spaced fixed contacts, a rotor having a series of peripheral abutments and oppositely laterally ofi-set portions cooperable with said contact plate to successively swing the latter in opposite directions, and a reciprocable plunger element engageable with said abutments to revolve the rotor by successive steps equal to the distance between the successive off-set portions thereof.

5. In a switch, an oscillatory contact plate having projections forming a recess, a rotor having an annular series of abutments projecting outwardly from its periphery and equally spaced oppositely laterally off-set portions cooperable with said recess to oscillate said plate in a plane and successively in opposite directions, and a plunger element engageable with said abutments to revolve said rotor by steps equal to the distance between the successive ofi-set portions thereof.

6. In a switch, an oscillatory contact plate having projections forming a recess, a rotor having an annular series of abutments projecting outwardly from its periphery and equally spaced oppositely laterally off-set portions cooperable with said recess to oscillate said plate, a plunger element engageable with said abutments to revolve said rotor by steps equal to the distance between the successive off-set portions thereof, and means independent of the plunger element resiliently engaging said rotor to restrain the rotation thereof by said element and being engageable with said abutments to positively prevent revolution of the rotor in the opposite direction.

7. In a switch, an oscillatory contact plate having integral spaced projections forming a recess, a rotor having an annular series of abutments projecting outwardly from its periphery and equally spaced oppositely laterally oif-set portions cooperable with said recess to oscillate said plate in a plane, a plunger element engageable with said abutments to revolve said rotor by steps equal to the distance between the successive off-set portions thereof, and resilient means coacting with said rotor independently of said plunger element and with said plate to frictionally restrain the movements thereof.

8. In a switch, an oscillatory contact plate having integral spaced projections forming a recess, a rotor having an annular series of peripheral abutments and equally spaced oppositely laterally off-set portions cooperable with said recess to oscillate said plate in a plane, a plunger element movable transversely of the plane of oscillation of said plate and engageable with said abutments to revolve said rotor by steps equal to the distance between the successive off-set portions thereof, and a helical compression spring for simultaneously urging said plunger element longitudinally in one direction and laterally toward said rotor.

9. In a switch, a main casing having an open end and a tubular extension projecting from the opposite end thereof, a contact carrying plate forming a closure for said open casing end, a contact plate pivotally mounted upon said carrying plate and movable within said casing approximately parallel to said carrying plate, a rotor mounted within said casing and cooperating with said contact plate to oscillate the latter in a plane, said rotor having a series of peripheral abutments, a plunger element cooperable with said abutments to revolve said rotor and extending from within said main casing through said tubular extension, a cap secured to said plunger element and slidably embracing the end of said tubular extension remote from said main casing, and a compression spring within said tubular extension coacting with said cap to move said plunger element longitudinally and with said element to urge the same laterally toward said rotor.

JOEL R. THORP. HOLDRIDGE W. MARSH. 

